In order to obtain X-ray images of interior structures of a body, such as a piece of luggage or the body of a patient, various types of imaging systems are employed. In one prior art imaging system illustrated in FIG. 1, an exemplary radiologic imaging system 200 may include a C-arm radiography system 102 configured to acquire projection data from one or more view angles around a subject, such as a patient 104 positioned on an examination table 105 for further analysis and/or display. To that end, the C-arm radiography system 102 may include a gantry 106 having a mobile support such as a movable C-arm 107 including at least one radiation source 108 such as an x-ray tube and a detector 110 positioned at opposite ends of the C-arm 107. In exemplary embodiments, the radiography system 102 can be an x-ray system, a positron emission tomography (PET) system, a computerized tomosynthesis (CT) system, an angiographic or fluoroscopic system, and the like or combination thereof, operable to generate static images acquired by static imaging detectors (e.g., CT systems, MRI systems, etc.) prior to a medical procedure, or real-time images acquired with real-time imaging detectors (e.g., angioplastic systems, laparoscopic systems, endoscopic systems, etc.) during the medical procedure, or combinations thereof. Thus, the types of acquired images can be diagnostic or interventional.
The radiation source 108 includes an emission device configured to emit the x-ray beams 112 towards the detector 110 that includes a plurality of detector elements that may be similar or different in size and/or energy sensitivity for imaging a region of interest (ROI) of the patient 104 at a desired resolution.
The C-arm 107 may be configured to move along a desired scanning path for orienting the x-ray source 108 and the detector 110 at different positions and angles around the patient 104 for acquiring information for 3D imaging of dynamic processes. To control this motion, the C-arm system 102 includes control circuitry 114 configured to control the movement of the C-arm 107 and/or the table 105 along the different axes based on user inputs and/or protocol-based instructions. Control circuitry 114 for the system 200 may include a control mechanism 204 and associated computing device 214 configured to control position, orientation and/or rotation of the table 105, the gantry 106, the C-arm 107 and/or the components mounted thereon in certain specific acquisition trajectories.
The detector 110 may be positioned on the C-arm 107 opposite the x-ray source 108 or can be disposed on or within the table 105 below the area or region of interest of the patient 104 to be imaged. The detector 110 includes a plurality of detector elements 202, for example, arranged as a 2D detector array, for sensing the projected x-ray beams 112 that pass through the patient 104. The detector elements 202 produce an electrical signal representative of the intensity of the impinging x-ray beams 112, which in turn, can be used by the computing device 214 to estimate the attenuation of the x-ray beams 112 as they pass through the patient 104 to provide an image on a display 218, as is known. In another embodiment, the detector elements 202 determine a count of incident photons in the x-ray beams 112 and/or determine corresponding energy. Particularly, in one embodiment, the detector elements 202 may acquire electrical signals corresponding to the generated x-ray beams 112 at a variety of angular positions around the patient 104 for collecting a plurality of radiographic projection views for construction of X-ray images, such as to form fluoro image(s).
In prior art imaging systems 200, the detector 110 is stationary, either relative to the x-ray source 108, as in the illustrated system 200 of FIG. 1, or to a support for the patient 104, i.e., the table 105. By making the detector 110 stationary, it is possible to locate the patient 104, and in particular the region of interest (ROI) to be imaged, in position relative to the detector 110 and then to move the x-ray source 108 in the proper orientation relative to the detector 110 to obtain an image of the ROI.
In these prior imaging systems 200, it is often difficult to properly orient the x-ray source 108 relative to the object or patient 104 to be imaged, particularly when the ROI is covers a relatively large are of the object or patient. This results from the small size of the detectors 110 that are currently utilized, e.g., detectors 110 that are 10″×12″ or 40″×41″. Further, even when the size of the detector 110 is sufficient to encompass the entire ROI, in order to obtain sufficient images of the ROI for review, it is often necessary to move the object/patient 104 and/or the x-ray source 108 relative to the detector 110, and often to reposition the detector 110 as well, in order to position the x-ray source 108 at the desired angles relative to the ROI to obtain the proper images. The sequential nature of this process to obtain these images results in a very slow and laborious process for obtaining the images. Further, in certain situations, the object/patient 104 cannot be moved, such as where the patient 104 is in critical condition and/or has injuries that prevent the patient 104 from being able to move, which renders the imaging system 202 unable to obtain the desired images of the object/patient 104.
Accordingly, it is desirable to provide an imaging system and associated detector with the capability to accommodate multiple positions of the x-ray source for obtaining images of an ROI without associated movement or positioning of the detector and/or the object/patient to be imaged.